1. Technical Field
This invention relates to a network; and more particularly relates to a frame relay network having frame relay nodes connected by trunk lines.
2. Description of Related Art
In the prior art, Frame Relay standards define two categories of traffic subscription for data entering a frame relay network. One is committed data and the other is excess data. A Frame Relay traffic network must allocate sufficient bandwidth on a trunk line connecting frame relay nodes to meet various obligations for carrying subscribers"" committed and excess data. The goal is to maximize the utilization of the total bandwidth of each trunk line in the Frame Relay traffic network.
For a subscriber call having committed data, a common approach is to fully allocate bandwidth equal to a maximum burst rate of the subscriber call. Bandwidth so allocated for committed data is allocated exclusively for that particular subscriber call. This guarantees that the bandwidth is available whenever the subscriber call provides data at the maximum burst rate. For every call subscribing to committed data, a new separate bandwidth is allocated on the trunks as the call sets up.
However, one disadvantage of the prior art frame relay system is that in many networks a large number of frame relay calls which subscribe do not send data constantly at the maximum burst rate. Thus, the trunk bandwidth allocated for that subscriber call goes unused many times.
The basic idea of the present invention is to share the same bandwidth with multiple subscribers at a time by selectively oversubscribing the total bandwidth of a trunk line connecting frame relay nodes.
The present invention features a frame relay network having a network management system in combination with frame relay nodes.
The network management system provides frame relay oversubscription trunk and connection parameter signals to the frame relay nodes, which contain information about how to allocate the bandwidth of the trunk lines connecting the frame relay nodes. The network management system uses a graphical user interface program for receiving frame relay oversubscription trunk and connection parameters from a network supervisor that are formatted into the frame relay oversubscription trunk and connection parameter signals.
The frame relay nodes respond to the frame relay oversubscription trunk and connection parameter signals, for providing a frame relay oversubscription connection control signal from one frame relay node to another frame relay node depending on the frame relay oversubscription trunk and connection parameter signals.
Each frame relay node includes a node control board, one or more frame relay line interface boards, and a control bus for connecting the node control board to the one or more frame relay line interface boards. The one or more frame relay line interface boards may include either a frame relay low speed line interface board, a frame relay medium speed line interface board, a frame relay high speed line interface board, or a combination thereof.
The network management system, the node control board and the frame relay line interface board may comprise microprocessor-based circuitry for running respective software programs to implement the oversubscription scheme. The microprocessor-based circuitry has a combination of a microprocessor, a random access memory, a read only memory, an input/output device, and an address, control and data bus for connecting the combination.
The frame relay node can provide monitoring information signals back to the network management system that contain information about the current levels of data traffic for the exclusive committed data maximum burst signal, the shared committed data maximum burst signal, the excess committed data maximum burst signal, the total committed burst signal, or the combination thereof. The network supervisor may change the frame relay oversubscription trunk and connection parameters from time-to-time depending on the performance of the frame relay network as well as any feedback gained from the monitoring information.
One advantage of the present invention is that the benefit of oversubscription is that a customer needs fewer lines, cards, etc. to comprise the frame relay network.